A combustion chamber arrangement comprises an annular combustion chamber, an outer casing surrounding the annular combustion chamber, a plurality of fuel injectors arranged to supply fuel into the annular combustion chamber, an inner casing and a stage of combustion chamber outlet guide vanes arranged at the downstream end of the annular combustion chamber. The annular combustion chamber comprises an annular upstream end wall, a radially inner annular wall, a radially outer annular wall, a radially inner annular cowl and a radially outer annular cowl. The radially inner annular wall is secured to the annular upstream end wall, the radially outer annular wall is secured to the annular upstream end wall, the radially inner annular cowl is secured to the annular upstream end wall and the radially outer annular cowl is secured to the annular upstream end wall. The annular upstream end wall has a plurality of circumferentially spaced apertures, each fuel injector is arranged in a respective one of the apertures in the annular upstream end wall and each fuel injector is secured to the outer casing.
In one known arrangement the radially outer annular cowl and the radially outer annular wall are secured to the annular upstream end wall by a bolted joint and the radially inner annular cowl and the radially inner annular wall are secured to the annular upstream end wall by a bolted joint. The downstream end of the radially inner annular wall is mounted on the inner casing or the downstream end of the radially inner annular wall is mounted on the inner casing and the downstream end of the radially outer annular wall is mounted on the outer casing such that the downstream end of the inner annular wall is constrained at least axially to the inner casing or the downstream ends of the inner and outer annular walls are constrained at least axially to the respective inner and outer casings.
A disadvantage of this arrangement is that the axial loads applied to the inner casing and the thermal expansion of the inner casing results in considerable movement of the inner casing relative to the outer casing. The annular combustion chamber is constrained axially to the inner casing or the radially inner ends of the stage of combustion chamber outlet guide vanes and hence a stress is induced in the annular combustion chamber as the inner and outer casing move relative to each other during operation of the gas turbine engine.
In another known arrangement the radially inner annular cowl and the radially outer annular cowl are integral with the annular upstream end wall and are produced by casting, the radially outer annular wall is secured to the annular upstream end wall by brazing or welding and the radially inner annular wall is slidably mounted on the annular upstream end wall. The annular upstream end wall is mounted on the outer casing and the downstream end of the radially inner annular wall is mounted on the inner casing.
A disadvantage of this arrangement is that it is difficult and expensive to manufacture the annular combustion chamber and it is difficult to assemble, disassemble and repair the annular combustion chamber.
The present disclosure seeks to produce a combustion chamber arrangement which reduces, or overcomes, the above mentioned problem.